Footnotes

• Contributors BP drafted the letter, and SM reviewed the letter and revised the final version.

• Funding The authors have not declared a specific grant for this research from any funding agency in the public, commercial or not-for-profit sectors.

• Competing interests BP has received an investigator-initiated research grant from AbbVie Corporation and compensation as an advisor and speaker for AbbVie. SM has no conflicts to declare.

• Provenance and peer review Commissioned; internally peer reviewed.

• Correction notice This article has been amended slightly since it was published Online First. In the first paragraph ‘due to several dysmorphic features’ has been changed to ‘as a result of structural variants’.

• Patient consent for publication Not required